The common indoor/outdoor plant most people know as geranium is, botanically, Pelargonium. Considered here are true geraniums, which are mostly hardy plants. Many types bloom over a long period, bearing flowers that are attractive though not always as showy as those of pelargoniums. Carried singly or in few-flowered clusters, blossoms have five overlapping petals that look alike. (Pelargonium flowers also have five petals, but two point in one direction, while the other three point in the opposite direction.) Colors include blue, purple, magenta, and bluish rose; some are pure pink or white. Beak-like fruit that follows the flowers accounts for the common name “cranesbill.” Leaves are roundish or kidney-shaped, lobed or deeply cut; plants may be upright or trailing.
Good in rock gardens and perennial borders; some are useful as small- or large-scale groundcovers. A few shrubby species are good for holding slopes. Best climates for most geraniums are cool- and mild-summer regions, where the plants can grow in full sun or light shade. In hot-summer areas, give afternoon shade. South African species are less cold-hardy but are more tolerant of heat and afternoon sun. All species appreciate moist, well-drained soil.
Some geraniums benefit from being cut back after flowering or in the fall. Clumps of most types can be left in place for many years before they decline due to crowding; at that point, divide in early spring. Increase by transplanting rooted portions from a clump’s edge; or take cuttings. Many produce lots of seedlings, and some can become naturalized pests.Geranium maderense
Dramatic native of Madeira likes moist conditions and shade. Has the largest of all geranium leaves (to 2 ft. long)—overlapping, glossy, deeply divided, shaped like giant snowflakes. Reddish brown leafstalks help buttress the 3–4-ft. “trunk” supporting hundreds of densely packed, fuzzy buds and magenta-eyed deep pink blossoms to 1 1/2 in. wide. Blooms early spring through midsummer. Biennial or short-lived perennial; dies after blooming but spawns many seedlings.
Evergreen from southwestern Australia. Thick rootstocks send up fans of dark green, swordlike leaves a...
Grows to 20–80 ft. tall and wide. Slim blue-green leaves turn bronze in winter. Bark is iron-bla...
From Australia. Spreading, mounding growth to 3–6 ft. tall, 6–10 ft. across. Closely set, ...